1. Field of the Invention
The present invention relates to a method of predicting a failure of a load, such as electronic equipment and parts, as well as a control unit and a load controlling system using the method. More particularly, the present invention concerns a method of predicting a failure, which is capable of diagnosing the durable life of electronic equipment and parts serving as loads, and of notifying an operator to the effect that the load has approached a limit of its life and that replacement of the electronic equipment or parts is prompted, as well as a control unit and a load controlling system using the method.
2. Description of the Related Art
As a conventional failure predicting method of this type and a load controlling system using the same, those which are disclosed in, for example, Japanese Patent Unexamined Publication No. Hei. 5-56555 are known.
In the invention disclosed in Japanese Patent Unexamined Publication No. Hei. 5-56555, there is provided a failure predicting apparatus, in which characteristic-amount data, such as a making current value and a steady-state current value, are extracted in advance from a load current waveform due to the normal switching action in an early period and are stored as reference characteristic-amount data in a storage means, and which effects the prediction and diagnosis of a failure by means of a inferring means through fuzzy inference on the basis of the characteristic-amount data extracted from the load current waveform and the reference characteristic-amount data each time an input is given to a relay.
However, with such a conventional failure predicting apparatus, it is necessary to determine membership functions for effecting the fuzzy inference for each of various loads, and, in order to determine such membership functions, it is necessary to extract different characteristic amounts for each of the loads. Hence, there has been a technical problem in that the scale of the apparatus increases, and software becomes complicated.